The present invention relates to a method according to the preamble of the appended claim 1 for installing services in a data processor. The invention relates also to a system according to the method and to an external device, such as a wireless communication device.
Data transmission between computers and devices connectable to them is typically implemented by means of a cable, so that a data transmission cable is connected between these devices. In office use there may also be several computers and other external devices, such as printers, which are connected locally to the local area network. This local area network is normally implemented with cabling, such as Ethernet cabling. Recently, however, wireless coupling methods have been developed, for example, data transmission systems for short distances, working by infrared and radio signals. The use of these wireless data transmission systems is easier, because the user does not have to connect the cables to different devices, but it will be sufficient that the devices are in the operating range of the data transmission system. Regardless of the technique used to implement this data transmission system, defining the features of the devices and setting functional parameters is typically needed. The computer has to identify the types of the devices (printer, telecopier, wireless communication device, modem) communicating with it, in order to use the right data transmission mode. As a rule, this identification is conducted in such a way that the user starts up an installation program in the computer, in which all the required procedures for defining the device in question, in the operational environment of the computer are programmed. The device, such as a printer or a wireless communication device, is accompanied with a diskette or CD ROM, in which this installation program is located. In practice, this means that the installation program version is perhaps not the latest one at the moment of installation, wherein new features which are not at the user""s disposal may be introduced after the program is supplied. Thus the user has to buy a newer installation program version if s/he wants to use the new features.
Recently this identification of the devices has been developed to be more automatic, wherein the computer tries to identify the devices which are in data transmission connection with it. The term xe2x80x9cplug ang playxe2x80x9d is used for this method. Hereinbelow, the term xe2x80x9cautomatic identificationxe2x80x9d will be used for this method in this description. Identification is implemented by means of data transmission between the computer and the external device, in which the device transmits information required in the identification to the computer. This, however, requires that a device driver or a corresponding program, suitable for the identification of the device, is installed in the computer.
Infrared data transmission has been found relatively effective in short distances, because connecting cables can be avoided and various devices can be placed more freely. Nevertheless, in infrared data transmission, attention has to be paid to the fact that between communicating devices, there either has to be unobstructed visibility or the possibility to establish optical connection via reflecting surfaces. Different standards have been developed for this kind of data transmission, for instance the IrDA standard (Infrared Data Association). FIG. 1 presents a system, in which infrared data transmission is used between different devices. As an example, the system presents a desk-top computer PC to which a lap-top computer LPC, printer PR, and different wireless communication devices, such as mobile phones MS1, MS2, MS3 are connectable by means of infrared data transmission. In infrared data transmission according to the IrDA standard, it is possible to identify the infrared devices in the vicinity of this desktop computer. This desktop computer in a system according to FIG. 1 is a so-called host device which functions as a kind of a device controlling the system. According to the IrDA standard, in each device which contains means for infrared data transmission, identification data is stored, such as the name of the device, the dynamically definable address of the device, and State variables for indicating services supported by the device. The state variables indicate, for instance, which service class the device in question belongs to. Such service classes are, for example, a personal computer, a printer, a xe2x80x9cplug and playxe2x80x9d type device, a telecommunication terminal (telephone), etc. Thus, the wireless communication devices in the vicinity of the host device can be defined on the basis of this service class definition by examining the value of the telecommunication terminal state variable. The host device stores the information on the infrared data transmission devices it has detected and identified in its storage means.
In a situation where a new device suitable for infrared data transmission enters the vicinity of the host device, a corresponding external device identification is performed. This external device is detected for example in such a way that the host device transmits at intervals a query message, to which a reply message is transmitted by the devices that are located in the vicinity of the host device and are suitable for infrared data transmission. This reply message is received by the host device and used for defining, for example, the service class of the external device.
The aforementioned data transmission system according to the IrDA standard is based on a sandwich structure of seven layers called OSI (Open Systems Interconnection) presented by the International Standards Organization ISO. The IrDA standard protocol stack comprises the lowermost layer of the said OSI sandwich structure, i.e. the physical layer, the data link layer above that, the following network layer, and the uppermost layer, i.e. the application layer.
The implementation of the physical layer may vary in different devices. Usually, data transmission according to the IrDA-SIR specification is used, by means of which the speed 115.2 kbit/s can be achieved. Also faster infrared data transmission has been suggested for the IrDA standard (FIR, Fast Infra Red) in which the speeds 1.152 Mbits and 4 Mbits have been defined.
The abbreviation IrLAP is used to indicate the data link layer protocol. This protocol supports the identification of devices and the service that secures data transmission reliability. In this protocol layer other devices are also informed that infrared data transmission is available in this device.
The abbreviation IrLMP is used to indicate the network layer protocol. This protocol supports connection set-up on the service level and multiplexing of different data transmission streams.
The application layer contains services needed by the applications used in the device. One service required in every IrDA device is a so-called Information Access Service (IAS). This information access service includes a so-called server service and a client service. The client service is able to make enquiries to the server service in order to find out which services are supported by the host device. The server service retrieves the information from a local database, such as a database stored in the storage means of a desktop computer. This database contains service-specific information.
Devices supporting IrDA data transmission can be either solely transmitting or solely receiving devices, or devices which are capable of both transmitting and receiving. All transmitting devices must, however, be able to determine whether there is other infrared data transmission on the go in the vicinity at the moment of transmission, because only one device is allowed to transmit at a time in the system.
If a device starting transmission detects another device also transmitting at that moment, the device waiting for the moment of transmission examines again after a while whether there is infrared data transmission on the go. When no other data transmission is detectable, the device waiting for transmission begins its own transmission.
The wireless communication devices presented in the system of FIG. 1 may contain very different features even though they all are telecommunication terminals. One wireless communication device may only contain basic features such as answering a call and call set-up. Another wireless communication device may also contain features such as sending and receiving text messages and other data features. A third wireless communication device may, in addition to telephone features also contain data processing features, such as calendar functions, notebook functions, or the like. With the help of a device identification method according to prior art, it is thus not possible to find out which wireless communication device type is in question, and thus some of the features of the wireless communication device may remain un-utilized when it is locally connected, for example, with a desktop computer or a lap-top computer. Another drawback in the systems according to prior art is that the identification data is not stored in the computer functioning as a host device, wherein this data always has to be defined when a device is connected in a data transmission connection with the host device.
One purpose of the present invention is to bring about a method for identifying an external device in a system which includes means for transmitting information between a host device and external devices. The method according to the present invention is primarily characterized in what will be presented in the characterizing part of the appended claim 1. The system according to the present invention is primarily characterized in what will be presented in the characterizing part of the appended claim 15. The external device according to the present invention is mainly characterized in what will be presented in the characterizing part of the appended claim 19. The invention is based on the idea that from external devices in the vicinity of the host device, additional information is accessed in order to determine the features of the wireless communication device, and a service packet is loaded in the host device, corresponding to the identified type of the external device and containing at least one service to control the functions of the external device.
With the present invention, considerable advantages are achieved compared with methods according to prior art and wireless communication devices. When using a method according to the invention, external devices in the vicinity of the host device, such as wireless communication devices, can be distinguished according to their features, wherein control modes best suitable for each device can be used in their control. In this way the features of the devices can be utilized better in a system in which it is possible to arrange external devices in a data transmission connection with a data processor, such as a computer. A method according to the invention enables updating the system with new identification methods according to the need, wherein the method is easily extendable. Furthermore, in the method, the features of the identified wireless communication devices can be stored, wherein different procedures can be performed for identified devices and new devices in the system.
In a system according to the invention, it is possible to load, for example the control software of a wireless communication device, if necessary, even by means of the global Internet information network directly from the server of the manufacturer, wherein it is always possible to retrieve the latest software suitable for the use of the wireless communication device in question. Thus, a program diskette, which would often contain an outdated program version, need not necessarily be supplied with the wireless communication device.